Combination coal and gas range with automatic oven heat control



y 1944. A. STOCKSTROM ET AL 1 2,353,278

COMBINATION COAL AND GAS RANGE WITH AUTOMATIC OVEN HEAT CONTROL Filed Nov. 30, 1940 3 Sheets-Sheet l f fioqmsfvan/ e 'P 'xcrwzsswagz Je ar 63%,

ITO/PAQEYS y 11, 1944- A. STOCKSTROM ETAL 2,353,278

COMBINATION COAL AND GAS RANGE WITH AUTOMATIC OVEN HEAT CONTROL Filed Nov. 30, 1940 5 Sheets-Sheet 2 poooqowooc gr 4, a Vm 1944- A. STOCKSTROM ETAL 53, 73

COMBINATION COAL AND GAS RANGE WITH AUTOMATIC OVEN HEAT CONTROL Filed Nov. 5Q, 1940 3 Sheets-Sheet 5 III/ I l WWI/Viva;

Patented July 11, 1944 I N! if I S PAE Jersey Application November 30, 1940, Serial No. 368,970

(ill. 1-26-36) 18 Claims.

It is now common practice to automatically maintain within a range oven a'predetermined temperature by means of a thermoresponsive device which is subjected to the heat within the oven. Numerous thermoresponsive devices for accomplishing this result have been designed and are in common usage, but the majority of those now being utilized on ranges are of the so-called liquid fill type, by which is meant that the particular thermoelement in the oven. is filled with a liquid which expands in response to temperature increase. The thermoelement in the oven is commonly referred to as a bulb." Liquids of numerous kinds are used in these bulbs but they will stand approximately only 650 F. with" out breaking down and thereby rendering the thermostat inoperative to carry out the desired control.

The present invention pertains to a construction which makes it possible and practical to utilize a liquid filled thermostat in the oven of a combination range. A combination range is a range which is heated by two or more fuels which most commonly are coal and gas. Wood, coke or some other solid fuel can however be substituted for and burned in a grate of the range in place of coal. Although such ranges are commonly referred to as combination coal and gas ranges they can, as stated, burn solid fuel other than coal and the gas burner could be replaced by a liquid fuel type of burner.

When coal or other solid fuel is utilized as the heating medium of the oven extremely high temperatures can and very often do prevail in the oven, with the result that the liquid of the thermoelernent is broken down which necessitates the replacement of the thermostat, it being understood that the thermostat is for the purpose of automatically controlling the oven temperature when the gas or gaseous fuel burner is utilized to heat the oven.

The primary object of the present inventionv is to provide a construction wherein a liquid fill thermostat can be used in the oven of a combination range.

In the accomplishment of the foregoing object we provide a novel and practical means of protecting the thermoresponsive element from the excessive heat generated when the range is operating with a solid fuel.

Another object of the invention is to provide means which are fool-proof in that whenever the range is not operating with a gaseous fuel burner the thermoresponsive element is protected against injury should the range be operated with solid fuel, and at the same time to automatically insure that the thermoelement is subjected to the full oven temperature whenever the range is operated on gaseous fuel.

A still further object of the invention is to automatically change the fiuing arrangement of the oven as the gaseous fuel burner is brought into operation or the operation thereof is discontinued.

Other specific objects, novel features of construction, and advantages of the invention will appear from the following detailed description in conjunction with the accompanying drawings which illustrate one embodiment of the invention in a combination range.

In the drawings:

Fig. 1 is a longitudinal vertical sectional view through a combination range embodying the present invention. I

Fig. 2 is an enlarged detail view of that portion of the rearwall of the oven wherein are positioned the thermoresponsive element and the oven damper.

Fig. 3 is a vertical sectional view on the line 33 of Fig. 2.

Fig. 4 is a view similar to Fig. 2 viewing the rear wall of the oven from its back or outer side.

Fig. 5 is a side view of the construction appearing in Fig. 4, the view being partly in vertical section and schematic to the extent that the fuel valve for the oven gaseous fuel burner is illustrated.

Fig. 6 is a fragmentary vertical sectional view through the bottom of the range and oven and illustrates the passageway beneath the oven bottom.

Referring now to the drawings and first particularly to Fig. 1 thereof, it will be seen that in many respects the combination range illustrated is conventional in nature. At one end the range body is provided with a fire box A having a grate l upon which the coal, wood or other suitable solid fuel may be burned. Ashes of the burned solid fuel is directed into a. removable ash receptacle 2 by suitable baiiles 3.

The oven isdesignated as an entirety at B and has a wall 4 which is common to the fire box and ash pit 5. The oven is suspended or supported in separated relationship to the range solid cooking top 6, end wall 1 and bottom wall 8 to provide a surrounding flue made up of the flue portions 9, I0 and II. This is conventional construction to provide for the circulation around the oven of the hot products of combustion generated in the fire box A as indicated by arrows.

2 I2 stopping short of the wall 4 of the oven to provide a gaseous fuel burner chamber 13 the size of which is somewhat enlarged by flaring the lower end of the oven wall 4 outwardly as at' l4. Any suitable type of gaseous fuel burner C is disposed within this chamber and the hot prodnets of combustion generated thereby travel into the oven in the manner clearly indicated by arrows from which it will be seen that there is an inlet passageway l5 paralleling the oven end wall 4 and discharging into the upper end of the oven and that beneath the oven bottom there is a longitudinally extending passageway l6 having an inlet through the opening 52 of the end wall I2 and which communicates as at I! with the bottom area of the oven at that side thereof which is remote to the'burner.

Because it is conventional and not because it forms any part of the present invention, we have illustrated the range oven as being provided interiorly with a gaseous fuel broiler burner which will perform a broiling operation upon any foods supported upon a conventional rack or broiler pan which is adjustably supported within the oven upon suitable oppositely positioned supporting rails l8. Thus it will be seen that the gaseous fuel burner 0, like the solid fuel burner, is brought into operation when it is desired to use the oven for baking purposes.

The range has a second cookin top I9 and gaseous fuel burners therefor under the control of suitable gas cocks 22 and 23. The flow of fuel to the baking burner C and broiler burner D is under the control of a two-way valve H. A single valve for the two burners is used for the purpose which will hereinafter more fully appear.

The fuel that passes to the baking burner must pass through a thermostatically operated valve designated as an entirety by G. The operation of this valve is determinable by the setting of the calibrated dial 24 of this valve in combination with the liquid filled thermoelement or bulb E which is disposed within the range oven and connected to the valve G by a liquid filled tube F.

Inasmuch as liquid filled oven heat regulators are well understood by those skilled in this art, and inasmuch as the particular specific construction of regulator used forms no part of the present invention, a detailed description of this particular mechanism is unnecessary. It is sufilient to say that the thermoelement or bulb E will automatically maintain within the oven a temperature the degree of which is predetermined by the setting of the dial 24.

The oven is provided with an outlet damper R which when solid fuel is being used is in a closed position but which is automaticall opened and automatically closed, as will be hereinafterdescribed, when the fuel control valve H of the baking burner C is opened and closed.

The rear wall 25 of the oven, as will more clearly appear in Fig. 3 of the drawings, is provided with an opening at the inner side of which and within the oven is disposed a surrounding frame 26 which is of cast iron construction. The thermoelement or bulb E is positioned within the oven rear wall opening. To avoid the necessity of a large wall opening the bulb is formed into substantially an S-shape and is suitably supported upon a pair of upwardly extending spaced arms 21 which can be made as a part of the opening frame 26. To be more precise, the bulb is form flanges 28 and 29 which abut the opening frame 26 and rear wall 25 of the oven respectively to act as stops and also to provide for a substantially heat-tight seal with the parts that they engage. It is to be noted that the face of the frame 26 which is engaged by the hood flange 28 is slightly tapered as at 29 to provide for more accurate engagement and seating of the flange.

The combined shield and hood is rotatably supported in the opening upon a pair of stub shafts 30 and 3|. The liquid filled tube F which joins the thermoelement and the thermooperated valve mechanism G also appears in Figs. 2 and 4 of the drawings. Having reference particularly to Figs. 2 and 5 of the drawings it will be seen that the stub shaft 3| of the hood is provided with a segmental gear S which is rotatable within a housing 32 having an open side at the rear of the oven wall, which wall is incidentally the rear wall of the range, and that this gear has operative engagement with a series of perforations 33 in the lower end of an elongated vertically extending rod or bar P mounted for vertical movement on the rear face of the oven rear wall 25 in a pair of suitable guides 34 and 35.

The oven damper R is provided with a. shaft 36 which is pivotally mounted in a pair of bearings 31 and 38. This shaft is provided with a crank arm 50 provided with an extension arm 39 having attachment with a fixed cross arm 40 carried by the rod or bar P at its upper end above the upper guide 34.

A substantially horizontally disposed arm 4| is at one end pivotally attached as at 42 to the bar or rod P intermediate its ends while its other end is pivotally supported as at 43 to a suitable fitting 44 on the rear oven wall 25. The cross arm 4| intermediate its length is provided with a longitudinally extending slot 53 within which a pin 45 is disposed. This pin is also disposed within the horseshoe-shaped .trackway 46 of a cam T which is carried on the end of a rod 41 which by suitable instrumentalities has operative connection as at 48, Fig. 5 of the drawings, with the fuel valve H that controls the flow of fuel to the oven baking burner C and broiler burner D.

From the construction thus far described it will be seen that when the cook or valve H is rotated to an open position to permit operation of the burner C this rotation will be transmitted to the cam Rotation of the cam T by the opening of tlw. valve will lower the cross arm 4| and lower the ind P which in turn will cause the thermobulb shield L to be rotated into the position illus trated in Fig. 2 of the drawings and at the same time open the oven damper R. Thus the thermobulb will be subjected to the oven temperature so that it can control the same and the oven damper will be open to permit the hot products of combustion to circulate in and escape from the ovens. When the fuel valve H is closed the reverse operation is obtained and the bulb shield and oven damper are moved into the positions illustrated in Fig. 4 of the drawings. That is to say, the oven damper is closed and :the thermal hood shield covers and completely isolates the thermobulb from the high temperatures which will prevail in the oven through the operation of the solid fuel range burner.

With the hood in a shielding position in respect to the thermobulb it will be seen that the bulb is in actuality exteriorly positioned in respect to-the oven, due to the fact that itis disposed in a plane behind the oven wall 25, and that the air within the room wherein the range is being used is free to contact and circulate over the bulb to prevent any possibility of its being overheated and damaged by any heat to which it will be subjected due to its close proximity to the oven. I

The two-way gas cock H by which fuel is controlled to both the broiiing burner D and baking oven C avoids any possibility of simultaneous operation of these two burners.

Thus it will be seen that we have provided a construction wherein automatic thermostatic control of the oven temperature in a combined solid'and gaseous fuel range can be provided with assurance that the liquid filled bulb of the heat control apparatus will be safeguarded from injury and have also provided for automatically properly fluing the oven for operation of the range with either solid or gaseous fuel.

The precise construction illustrated and described is not essential to the accomplishment of the objects and results of our invention, and the invention therefore is to be limited only within the scope of the hereinafter appended claims,

We claim:

1. In a range or the like, an oven, a solid fuel and a gaseous fuel burner optionally operable to heat said oven, means to convey the heat gener-- ated by said solid fuel burner to the oven, a thermoresponsive member positioned out of heat transfer relationship with the said means for conveying to the oven the heat generated by said solid fuel burner, said thermoresponsive member being operable by the heat within said oven for controlling the flow of fuel to said gaseous fuel burner and thereby maintaining within said oven a predetermined temperature, a valve for initially turning on and off the fuel to said gaseous fuel burner, a shield movable in respect to said thermoresponsive member to optionally isolate said member from the heat within said oven,

and a connection between said shield and said valve operable to position said-shield to isolate said thermoresponsive member from the oven heat when said valve is in a closed position to prevent the flow of fuel to said gaseous fuel burner.

2, In a range or the like, an oven, a solid fuel and a gaseous fuel burner optionally operable to heat said oven, means to convey the heat generated by said solid fuel burner to the oven, a thermoresponsive member positioned out of heat transfer relationship with the said means for conveying to the oven the heat generated by said solid fuel burner, said thermoresponsive member being operable by the heat Within'said oven for controlling the flow of fuel to said gaseous fuel burner and thereby maintaining within said oven a predetermined temperature, a valve for initially turning on and off the fuel to said gaseous fuel burner, said oven provided with a flue outlet opening and a damper for closing the same, a member movable into a position to isolate said thermoresponsive member from the heat within said oven, a connection between said valve and said damper and said movable member, and said connection operable to close said damper and isolate said thermomember from the heat of said oven when the valve is in a closed position.'

3. In a range or the like, an oven, a solid fuel burner and a gaseous fuel burner optionally operable to heat said oven, means to convey the heat generated by said solid fuel burner to the oven, thermoresponsive means for controlling the how of fuel to said gaseous fuel burner, said thermoresponsive means including a thermoelement positioned out of heat transfer relationship with the said means for conveying to the oven the heat generated by said solid fuel burner, the said thermoresponsive element being positioned exteriorly of the oven and behind 'an opening in said oven through whichthe heated air in said oven can pass for contact with said thermoelement, a member for closing said oven opening to isolate said thermoelement from the heat within said oven, said oven provided with an outlet opening and a damper closure therefor, a valve for initially turning on and cutting off the flow of fuel to said gaseous fuel burner, and a connection between said valve and said damper and said member operable to close said oven opening in front of said thermoresponsive element and causing the closing of said damper when said valve is moved to a closed position.

4. In a range or the like, an oven to be heated,

a solid fuel burner and a gaseous fuel burner optionally operable for heating said oven, means to convey the heat generated by said solid fuel burner to the oven, a valve for controlling the flow of fuel to said gaseous fuel burner, an 0\ en heat regulator including'a thermoresponsive member positioned out of heat transfer relationship with the said means for conveying to the oven the heat generated by said solid fuel burner, said thermoresponsive member being operable by the heat within said oven for controlling the flow of fuel to said burner, a cam, said cam being rotatable by said fuel valve, a movably mounted shield operable to isolate said thermoresponsive member from the heat within said oven, a connection between said cam and said shield, and said valve operating when moved to a closed position to move said shield into a position to isolate said thermoresponsive member from the heat within said oven.

5. In a range or the like, an oven to be heated, a solid fuel burner and a gaseous fuel burner optionally operable for heating said oven, means to convey the heat generated by said solid fuel burner to the oven, a valve for controlling the flow of fuel to said gaseous fuel burner, an oven heatregulator including a thermoresponsive member positioned out of heat transfer relation-' ship with the said means for conveying to the oven the heat generated by said solid fuel burner,

said thermoresponsivemember being operable valve acting when moved to a closed position to' simultaneously close said damper and move said shield to a position to isolate said theremoresponsive member from the heat within said oven.

6. In a range or the like, an oven, a solid fuel burner and a gaseous fuel burner optionally operable for heating the same, means to convey the heat generated by said solid fuel burner to the oven, an oven heat regulator including a thermoresponsive member positioned out of heat transfer relationship with the said means for conveying to the oven the heat generated by said solid fuel burner, said thermoresponsive member being operable by the heat within said oven for controlling the flow of fuel to said gaseous fuel burner, said thermomember being positioned exteriorly of the oven, an opening in said oven for permitting the flow of the hot air therein over said thermomember, a shield movably mounted in respect to said oven opening and said thermomember and in the form of a pocket having an open side, means to move said pocket whereby the open side thereof optionally faces the interior of the oven or faces the exterior of said oven,

and said pocket in either position closing said oven opening to seal the same against the escape of heat from the oven into exterior atmosphere.

7. A construction such as defined in claim 6 wherein, a valve is provided for initially turning on and cutting off the flow of fuel to said gaseous fuel burner, and a connection being provided between said valve and said pocket operating to position the pocket with its open side facing the exterior of the oven when the valve is in a closed position, whereby said thermomember is isolated from the heat within said oven and the air exterior of the oven can pass freely over the thermoelement.

8. In combination, a chamber to be heated, a solid fuel burner and a gaseous fuel burner optionally operable for heating said chamber, means I to convey the heat generated by said solid fuel burner to said chamber, a heat regulator including a thermoresponsive element out of heat transfer relationship with the said means for conveying to the oven the heat generated by said solid fuel burner, the said thermoresponsive element being operable to regulate the heat delivered to said chamber by said gaseous fuel burner, means for permitting the heated air within said chamber to contact and flow over said thermoelement, and means selectively operable to prevent contact of said heated oven air with said thermoresponsive element.

9. A construction such as defined in claim 8 wherein, a valve is provided for turning on and cutting off the delivery of fuel to said gaseous fuel burner, and said valve when moved to a closed position causing the operation of the means which prevents contact of the heated oven air with said thermoresponsive element.

' 10. In a range or the like, an oven, a solid fuel burner and a gaseous fuel burner optionally op erable to heat said oven, means to convey the heat generated by said solid fuel burner to the oven, a thermo-responsive element out of heat transfer relationship with the said means for conveying to the oven the heat generated by said solid fuel burner, the said thermo responsive element being operable by the heat within said oven for controlling the flow of fuel to said gaseous fuel burner to thereby automatically maintain a predetermined temperature within the oven when only the gaseous fuel burner is in operation, means operable to permit or to prevent the heat within said oven from reaching said thermo-responsive element, and means operable to operate said first named means, for the purpose described.

11. In a range or thelike, an oven, a solid fuel burner and a gaseous fuel burner optionally operable to heat said oven, means to convey the fuel burner to thereby automatically maintain a predetermined temperature within the oven when only the gaseous fuel burner is in operation, means operable to permit or to prevent the heat within said oven from reaching said thermo-responsive element, a valve for initially controlling the flow of fuel to said gaseous fuel burner, and said valve being operatively connected to said means to operate the same and to permit heat within the oven to reach the thermo-responsive element only when said valve is in an open position.

12. In a range or the like, a housing having therein an oven disposed in spaced relationship to 'several of the walls of said housing to provide around said oven a passageway, a burner communicating with said passageway, said passageway provided with an outlet to cause the hot products of combustion of said burner to circulate through said passageway and thereby heat said oven, a second heater for said oven comprising a gaseous fuel burner within said housing, a thermo-responsive element positioned exteriorly of said housing and remote from said passageway and adapted to control the supply of fuel to said gaseous fuel burner and thereby automatically maintain within said oven a predetermined temperature where said gaseous fuel housing provided with an opening for permitting the heat within said oven to reach said thermoresponsive element, and means for closing said opening to isolate the hot oven air from said thermo-responsive element when said oven is being heated by said first named burner.

13. A construction such as defined in claim 12 wherein, a valve is provided for initially controlling the flow of fuel to said gaseous fuel burner, an operable connection is provided between said valve and the meanst-for closing said oven and housing opening, and said connection is such that said opening is closed when said valve is closed and said opening is open when said valve is open.

14. A construction such as defined in claim 12 wherein, the means for closing said oven and housing opening is in the form of a pocket having an open side, and means is provided for moving said pocket to alternately position the closed side of said pocket at opposite sides of said thermo-responsive element.

15. A construction such as defined in claim 12 wherein, the means for closing the oven and housing opening is in the form of a pocket of a size to accommodate the thermo-responsive element and is provided with an open side, said pocket being mounted for oscillation, means to oscillate said pocket about said thermo-responsive element to selectively cause the open side of said pocket to be positioned in front of or behind said thermo-responsive element, and said pocket in either position closing said oven and housing opening.

16. In a range or the like a housing having an oven therein, a gaseous fuel burner for heating said oven, an automatic oven temperature conto said burner, said thermo-responsive element being positioned exteriorly of said housing, means permitting the heat generated in said oven to reach said thermo-responsive element, a second burner in said housing capable of heating said oven to a temperature suiliciently high to damage said thermo-responsive element, means for conveying the heat generated by said second burner to the oven, said thermo-responsive element being positioned out of heat transfer relationship with the said means for conveying to the I oven the heat generated by said second burner,

and means capable of operation when said last named burner is in operation for preventing the heat from within said oven reaching said thermo-responsive element.

1'7. A construction such as defined in claim 16 thermo-responsive element when said valve is open and the gaseous fuel burner is in operation.

18. A construction such as defined in claim 12 wherein, the hot products of combustion generated by the first named burner and traveling in said passageway do not and can not enter the oven, and the hot products of combustion generated by said gaseous fuel burners pass through said oven.

ARTHUR STOCKSTROM. GEORGE P. E'ICHELSBACH, JR. 

